As shown in FIGS. (1), (2), (3) and (4), in its simple form, an optical memory storage disk (Compact Disk) 1 is comprised of a formed disk 3 made of a transparent thermoplastic material such as polycarbonate. The upper surface 5 of disk 3 contains indentation 7, known as pits of varying sizes which are arranged in a continuous planar spiral with a very small radial spacing, (a), shown in FIG. (3), typically 1.6 microns. The pits 9 are coated with a very thin layer of metal, typically aluminum, to form a metallized reflective surface 11. For protection of surface 11, a protective surface/coating 13, typically acrylic lacquer or other transparent polymer or lacquer, is applied over surface 11. As such, the transparent thermoplastic disk 3 and coating 13 sandwich the memory storage metallized reflective surface 11 wherein a laser beam 15 is directed through the transparent disk 3 to read stored information.
The introduction of compact disks is a major step in the development of permanently recorded information media. As such, unless recovered, production defective disks and consumer-discarded disks represent a significant polymeric material loss and add to solid waste stream.
Therefore, a need exists for a method for recovering the polymeric material contained in defective and/or discarded compact disks.
The present invention provides a method and an apparatus for recovery of compact disks while maintaining the structural form and integrity of recovered disks for potential post-recovery uses such as punched washers, inexpensive electrical insulation washers or any application which requires the use of or may utilize thin disks.